Abstract: The current environmental technologies evaluation methods are mainly based on experts’ qualitative estimation and lack of comprehensive evaluation methods. Aiming at this problem and combined with the total ammonia discharge control requested by National Economic and Social Development Plan in 2011-2015 and the ammonia discharge reduction demand of nitrogen fertilizer industry, the index system and an integrated evaluation method for cleaner production technology evaluation based on ammonia discharge reduction was built. The weight of each index was obtained with analytic hierarchy process (AHP), and the discharge reduction technologies evaluated using grey correlation analysis method. The modeling process of the mathematical model of the integrated evaluation method was provided with an application example analyzed．